Development and illustration of a computationally convenient App for simulation of transient cooling of fish in ice slurry at sea

The use of ice slurry at sea to cool fish is widespread. Here we develop and illustrate a convenient simulation of fish cooling in ice slurry based on the transient cooling equation together with practical simplifying assumptions. It is convenient because the key input is the mass of the fish, which is routinely measured, and because it can be solved in standard spread-sheeting tools as a portable App. It is planned this innovative App would be calibrated for use in particular fisheries. Illustrative simulations for Southern BlueFin Tuna (Thunnus maccoyii) (SBT) show that a 35 kg fish at harvest (Ti = 28 °C) will cool to 5 °C (at thermal centre) in 10.23 h in slurry at a temperature maintained at 0 °C. Because predictions are demonstrated to be in good agreement with published Heisler charts it is concluded the simulation is free of programming and computational errors. Importantly, simulations reveal a small rise in the temperature of the slurry significantly affects the time for cooling. For example, if the temperature of the slurry rises to 2 °C, because of inadequate quantities of ice, the time to cool the SBT to 5 °C will be 12.27 h.